2017:16 Stress intensity factor solutions for circumferential cracks in cylindrical bars under axisymmetric loading and global bending


The case of a circumferential crack in a cylindrical bar has not been available in the ProSACC code. The need for such a geometry, especially considering nonlinear axisymmetric loading and global bending, has motivated the development of new stress intensity factor solutions, also known as K-solutions. These new K-solutions will be available in ISAAC, the successor to ProSACC.


The objective is to implement a capability in the computer code ISAAC to analyze long circumferential cracks in solid bars that may occur, for example due to thermal fatigue loadings. This means that both nonlinear axisymmetric loading and global bending loads have to be taken into account.


The K-solutions, which have been numerically determined, account for axisymmetric loading up to the 5th degree as well as global bending. The new K-solutions are limited by the crack depth a/R ≤ 0.8 which is a limit applied in ISAAC. Verification of the new K-solutions has been performed against available reference solutions and numerical results specifically obtained for selected cases. A degree of conservatism is introduced in the K-solutions as nonlinearities due to contact between crack faces from global bending loads have been omitted. The degree of conservatism is discussed in appendix A.